Knee arthroplasty, in which the knee is partially or completely replaced with a prosthetic knee, is a common surgical procedure performed to relieve pain or disability due to conditions such as osteoarthritis, rheumatoid arthritis and other forms of polyarthritis, cartilage defects, meniscus tears, and ligament tears. Knee arthroplasty typically replaces diseased or damaged joint surfaces of the knee, including surfaces on the femur, tibia and/or patella with artificial replacement components made of metal or plastic parts designed to allow for knee motion that is natural as possible. Natural knee motion is the result of a complex relationship between primary movements of flexion-extension and secondary movements of anterior-posterior translation and internal-external rotation. This complex relationship defines a functional envelope of motion, which varies from activity to activity.
Current knee replacement systems are unable to facilitate natural functional envelopes of motion, fail to engage the anterior and posterior cruciate ligaments and are therefore less-than-ideal for enabling natural knee movement over a wide range of activities of daily living. Current knee replacement systems also typically limit the activities of patients with knee replacements, and do not address the high performance needs and desires of younger or more active aging patients who typically participate in higher impact activities such as running.
Thus, there is a need in the knee replacement field to create an improved knee replacement system that facilitates natural knee movement over a broad range of activities. This invention provides such an improved knee replacement system.